Bioavailability of all-trans and cis-isomers of lycopene
Bioavailability of all-trans and cis-isomers of lycopene
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DOI：
10.1177/153537020222701012
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发表时间：
2002-11-01
影响因子：
3.2
通讯作者：
Erdman, JW
中科院分区：
文献类型：
--
作者：
Boileau, TWM;Boileau, AC;Erdman, JW
番茄红素是番茄中主要的类胡萝卜素，是美国人血清和组织中主要的类胡萝卜素之一。虽然在饮食来源中发现约90%的番茄红素是线性的，全反式构象，但人体组织主要含有顺式异构体。几个研究小组已经提出番茄红素的顺式异构体比全反式形式更好地吸收，因为顺式异构体的长度较短，顺式异构体在混合胶束中的溶解度较大，和/或顺式异构体聚集的倾向较低。雪貂是一种完整吸收类胡萝卜素的物种，研究表明，番茄红素剂量、胃和肠内容物含有6-18%的顺式番茄红素，而肠系膜淋巴分泌物含有77%的顺式异构体。雪貂研究支持顺式异构体比全反式番茄红素生物利用度更高的假设。体外研究表明，顺式异构体更易溶于胆汁酸胶束，并可能优先纳入乳糜微粒。这些发现的含义尚不清楚。大鼠似乎在人类报告的范围内在组织中积累番茄红素，这表明它们可用于研究番茄红素异构体对疾病过程的影响。研究正在进行中，以确定是否有生物差异之间的全反式和各种顺式异构体的番茄红素，其抗氧化性能或其他生物功能。
Lycopene, the predominant carotenoid in tomatoes, is among the major carotenoids in serum and tissues of Americans. Although about 90% of the lycopene in dietary sources is found in the linear, all-trans conformation, human tissues contain mainly cis-isomers. Several research groups have suggested that cisisomers of lycopene are better absorbed than the all-trans form because of the shorter length of the cis-isomer, the greater solubility of cis-isomers in mixed micelles, and/or as a result of the lower tendency of cis-isomers to aggregate. Work with ferrets, a species that absorbs carotenoids intact, has demonstrated that whereas a lycopene dose, stomach, and intestinal contents contained 6-18% cis-lycopene, the mesenteric lymph secretions contained 77%-cis isomers. The ferret studies support the hypotheses that cis-isomers are substantially more bioavailable then all-trans lycopene. In vitro studies suggest that cis-isomers are more soluble in bile acid micelles and may be preferentially incorporated into chylomicrons. The implications of these findings are not yet clear. Rats appear to accumulate lycopene in tissues within the ranges reported for humans, suggesting that they can be used to study effects of lycopene isomers on disease processes. Investigations are underway to determine whether there are biological differences between all-trans and various cis-isomers of lycopene regarding its antioxidant properties or other biological functions.